Polyamide oligomers and polymers have been intercalated into layered silicate materials in a variety of ways, as evidenced by U.S. Pat. Nos. 6,232,388 B1 ('388); 6,228,903 B1 ('903); and 5,877,248 ('248). The most common way to intercalate a polyamide oligomer or polymer into a layered silicate material is disclosed in the '388 patent wherein the layered silicate material is first treated with a surface modifying onium ion to expand the platelet spacing by ion-exchange with interlayer cations of the layered silicate material, followed by intercalation of the polyamide oligomer or polymer. Another method of intercalating a polyamide oligomer or polymer into a layered silicate material is disclosed in the '903 patent wherein an organic solvent is intercalated into the layered silicate material in an intercalating composition comprising the layered silicate, water, and the organic solvent and the intercalating composition is sheared to form a gel to bond the organic solvent to a surface of the layered silicate platelets. Thereafter the gel is dehydrated to a water content of 10% or less at which point the polyamide and a solvent for the polyamide contact the layered silicate material for intercalation of the polyamide oligomer or polymer. A third method of intercalating a polyamide oligomer or polymer into a layered silicate material is disclosed in the '248 patent, wherein neither an onium ion surface modifier nor an organic solvent is used, but the polyamide oligomer or polymer is directly intercalated into a wet layered silicate material to complex the amide functionality with the interlayer cations at the negative charge sites of the layered silicate material platelet surfaces.
Claytec U.S. Pat. Nos. 6,017,632; 6,096,803; and 5,853,886 teach intercalation of amino-functional reagents, e.g., curing agents for epoxy resins, by protonating the cation exchange sites of the layered silicate material prior to intercalation of the amino-functional reagents. Triton Systems U.S. Pat. No. 6,057,035 discloses nanocomposite compositions having enhanced thermal stability and performance by intercalating surfactants/compatibility agents into the layered silicate material that are phosphonium, preferably tetra-phenyl phosphonium.
The following Mitsubishi Gas Corporation (MGC) patents, and other MGC patents describe in detail the manufacturing of xylylenediamine-containing oligomers and polymers: U.S. Pat. Nos. 4,433,136; 4,438,257; 5,004,561; and 5,011,873. U.S. Pat. Nos. 4,398,642 and 4,535,901 describe multi-layer bottles containing a polyamide gas barrier layer, wherein the polyamide can contain a xylylenediamine group.
Others have recognized that layered silicate materials intercalated with alkyl quaternary ammonium ions (onium ions) are subject to thermal degradation, see Thermal Degradation Chemistry Of Alkyl Quaternary Ammonium Montmorillonite 2001 American Chemical Society, Chem. Matter 2001, 13, 2979-2990. The poor thermal stability is caused by a Hoffmann elimination reaction of the alkyl ammonium in the organoclays.
This long felt need to provide intercalated layered silicate materials, having excellent thermal stability, that provide improved structural properties, gas/liquid barrier properties, and/or increased temperature resistance when dispersed in a matrix polymer to form nanocomposite compositions has been solved in accordance with the intercalates, exfoliates and nanocomposite compositions described herein in a unique manner by intercalating the layered silicate materials with a xylylene diamine-containing oligomer or polymer, without using onium ion spacing agents.